Improvement in wood-screws



1. K. sTockTonf Wood-Screws. v

NO. 138,592, V Patented May 6.1873.

/ IW'V" Attorneys.

AM. PHam-urnqsnAPn/c on MY (ma/ands macsss UNITED STATES PATENT OFFICE.

JAMES K. STOCKTON, OF NEW YORK, N. Y.

IMPRQVEMENT IN WOOD-SCREWS.

Specification forming part of Letters Patent No. 138,592, dated May 6, 3873; application filed April 12, 1873.

To all whom it may concern:

Be it known that I, JAMES K. STOCKTON, of the city, county, and State of New York, have invented a new and Improved Wood- Screw, of which the following is a specification:

In the accompanying drawing, Figure 1 rep resents a vertical section of my improved woodscrew; and Fig. 2, a horizontal section of the same.

Similar letters of reference indicate corresponding parts.

The object of my invention is to furnish to workers in wood and the public generally a strong and effective wood-screw, which may be driven into the wood like a nail by the hammer, and withdrawn by the screw-driver like a common screw. The wood is penetrated, thereby cutting the fibers, so that a rigid wedge-like adhesion of the same is produced around the body of the screw. My invention consists of a triple-threaded screw with conical point, each thread being triangular in sec tion, the lower side beingperpendieular to the core, the upper side slanting downward.

In the drawing, A represents the woodscrew of the usual material, and provided with a common screw-head, a. Three triangular threads, b, are out around the cylindrical core d, each thread being of the shape of a rightangle triangle, with the hypotenuse slanting downward, the shorter side being placed under at a right angle to the core. The threads b are tapering off at the pointed end 6, of conical shape, which forms the entering part of the screw. Screw A is driven into the wood by the blows of the hammer, the'threads b cutting their way in the axis of the screw without deviating from the direction imparted, penetrating even the hardest parts of the wood. The force of the concussion gives a turn to the screw resembling the motion of a ball in the grooves of a rifle. The fibers of the wood close like wedges into the recesses between the threads, offering a powerful resistance to strain upon the screw, but releasing the same by turning in the opposite direction.

The advantages of a reliable hammer-driving screw are obvious, and will readily be appreciated by the trade.

Having thus described myinvention, I claim as new and desire to secure by Letters Patent The hammer-driving screw A, having triple triangular threads, slanting and rectangular to the core, with conical point, substantially as and for the purpose described,

Witnesses: JAMES K. STOCKTON.

PAUL GOEPEL, T. B. MOSHER. 

